Ahead of President Donald Trump’s visit to wildfire-ravaged California on Monday, Democrats charged over the weekend that his disregard for basic science had contributed to the worsening annual conflagrations, as well as to COVID-19.

Trump, meanwhile, seized on the shooting Saturday night of two Los Angeles County sheriff’s deputies to try to portray Democratic presidential rival Joe Biden as weak on law-and-order issues. Biden and his running mate, California Sen. Kamala Harris, rejected the notion such violence should go unpunished.

A Western tour that first took Trump to Nevada, where polls give Biden an edge, highlighted the president’s efforts to leverage voter fears about crime and violence amid the year’s protests against racial injustice. He said little about the pandemic, however, as he resumed rallies before close-packed, mostly unmasked crowds. And he suggested, as he has in past years, that Western states' bad forest management, not climate change, accounts for the intensity of wildfires in recent years.

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Trump reinforced his anti-crime rhetoric with a pair of tweets Sunday about the shooting in Compton, California, which authorities described as an ambush that left the two deputies critically injured.

“Animals that must be hit hard!” Trump wrote on Twitter, apparently referring to a lone suspect seen on surveillance video walking up to the deputies' parked car and firing several times. In another tweet, the president said: “If they die, fast trial death penalty for the killer. Only way to stop this!”

Both Biden and Harris, who served as California’s attorney general, expressed sympathy and concern for the deputies, a 31-year-old woman and a 24-year-old man who were recovering from surgery for multiple gunshot wounds and were expected to survive. The Democratic candidates separately called for the perpetrator to be brought to justice.

“Violence of any kind is wrong; those who commit it should be caught and punished,” Biden wrote on Twitter.

Trump’s surrogates, meanwhile, defended his handling of the COVID-19 outbreak, following a damning new account by Watergate reporter Bob Woodward.

In a combative exchange on CNN’s “State of the Union,” Trump adviser Peter Navarro sparred with host Jake Tapper over the president’s taped acknowledgement to Woodward in early February that he deliberately played down the gravity of the threat after being told the coronavirus was deadly and transmitted by air.

Bristling at Tapper’s contention that Trump misled the public, Navarro countered, “He was straightforward.” He parried with criticism of House Speaker Nancy Pelosi, D-Calif., the World Health Organization, China and the U.S. government’s top infectious disease specialist, Dr. Anthony Fauci.

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Tapper soon cut him off and ended the interview, noting to the broadcast audience that the United States has less than 5% of the world’s population but more than 20% of COVID-19 fatalities. The U.S. death toll is approaching 200,000.

Hours later in Nevada, Trump suggested that the coronavirus' spread is under control, a contention that has become a staple of his campaign.

“We are rounding the corner on COVID. We are rounding it rapidly, plus we have vaccines coming very soon,” he said at a roundtable with a few Latinos in Las Vegas.

The night before, the president held an open-air rally near Reno that lasted more than an hour and a half; another one, this time indoors, was planned for Sunday evening. Such gatherings defy his own administration’s public health guidance. Republican National Committee chairwoman Ronna McDaniel insisted on NBC’s “Meet the Press” that Trump was not modeling unsafe behavior by disparaging mask-wearing and rarely being seen in one.

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“I don’t think this is politically dividing at all,” she said of facial coverings. She said she and her family wear masks, but the choice to eschew them is “about individual freedoms.”

McDaniel also suggested the U.S. caseload — more than 6.5 million infections to date — is so high in part because “we do have more testing.”

The eruption of dozens of deadly wildfires devastating California, Oregon and Washington state, which have consumed millions of acres and produced apocalyptic orange-tinted skies, has become the latest national tragedy to divide rather than unite the parties.

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During his campaign swing, the president belittled West Coast states for poor “forest management,” as he has previously, ignoring the fact that federally managed land accounts for much of the burned acreage. At a rally last month in Pennsylvania, he referred to the need to “clean your floors ... clean your forests.”

Democratic officials say Trump is in denial about the root cause of the ferocious blazes.

“Talk to a firefighter if you think that climate change isn’t real,” said Los Angeles Mayor Eric Garcetti, interviewed on CBS' “Face the Nation.” He said the Trump administration has “put its head in the sand,” while local officials, Democrats and Republicans alike, have stepped up to combat climate change.

The wildfires, unprecedented in scope and ferocity, are “not just about forest management or raking,” Garcetti said.

Sen. Jeff Merkley, D-Ore., said on ABC’s “This Week” that the president’s blaming of forest management by state officials is “a big and devastating lie.”

Oregon’s Democratic governor, Kate Brown, interviewed on CBS, acknowledged “decades of mismanagement of our forests in this country” but also cited the necessity of tackling climate change. “We need to do both,” she said.